1. Field of the Invention
The present invention relates to a transducer. Particularly, it relates to a transducer with a signal unit that can produce sound and vibration as well as it can save space for effectuating the thickness minimization of a product.
2. Description of the Prior Art
There are various traditional transducers that can achieve the electro-acoustic converting function. For example, FIG. 6 exhibits a micro transducer. It includes:                a magnetic common base 71;        two external magnets 72 vertically disposed on two side of the magnetic common base 71;        a pair of magnetic plates 73 connecting with these two external magnets 72;        a cover 74 disposed on the magnetic plates 73 with a sound hole 741;        an internal magnet 75 secured on the magnetic common base 71; and        a polymer diaphragm 76 mounted between the cover 74 and the internal magnet 75.        
There is a gap D disposed between the polymer diaphragm 76 and the cover 74 for allowing vibration movement. Because the polymer diaphragm 76 and the cover 74 cannot be combined into one integral unit since gap D is required, it is not suitable for a product with an ultra-thin thickness.
FIG. 7 illustrates the second type of the traditional electronic device with an electric sound transducer. It includes:                two electricity-stopping vibration diaphragms 81;        a main body 82 disposed between these two electricity-stopping vibration diaphragms 81;        at least one perforated board 83 (with a plurality of holes) disposed between two electricity-stopping vibration diaphragms 81; and        many partitions 84 disposed between the perforated board 83 and the electricity-stopping vibration diaphragm 81.        
For a similar reason as mentioned previously, these electricity stopping vibration diaphragms 81 have to be separated from the perforated board 83. By virtue of this thickness limitation about the partitions 84, the product thickness cannot be minimized. So, it is not suitable for an ultra-thin product.
As shown in FIG. 8, the third traditional transducer includes:                a housing 91;        a speaker 92 that can be installed in the housing 91;        a piezoelectric vibrator 93 disposed on the housing 91; and        an upper cover 94 that can be covered on the housing 91.        
Regarding this device, the speaker 92 and the piezoelectric vibrator 93 are two independent elements or units. Hence, it causes the volume consuming problem. The speaker 92 and the housing 91 cannot be combined together. It also occupies certain volume. As a result, it still cannot apply to the ultra-thin product.